Diesel engine manufacturers and diesel fuel producers are continuously challenged to meet lower emission standards set forth by the U.S. Environmental Protection Agency (EPA), as well as other such agencies worldwide. These standards for both diesel and gasoline engines mandate limits for unburned hydrocarbons, carbon monoxide and oxides of nitrogen.
The toxicity of oxides of nitrogen and their ability to further react to produce additional toxic materials make them an undesirable by-product from the burning of hydrocarbons. When released into the atmosphere, these compounds and their products comprise what is commonly referred to as “smog”, a brownish haze seen over most major metropolitan areas.
The Engineering Society for Advancing Mobility Land Sea Air and Space mentioned in a paper that it appears that where a conventional diesel fuel is blended with a diesel fuel derived from a Fisher-Tropsch process, reductions in concentrations of emissions are generally reduced in a proportional fashion by adding increasing amounts of the Fischer-Tropsch fuel. In particular, emissions of oxides of nitrogen appear to follow this trend. (see SAE Technical Paper 2000-01-1912, page 6).
It would be useful to improve the methods by which reductions in emissions of oxides of nitrogen can be accomplished.